| Harrison to Orbetello | 4,181.57 mi (6,729.58 km) |
| Harrison to Oria | 4,534.12 mi (7,296.96 km) |
| Harrison to Oristano | 4,152.40 mi (6,682.64 km) |
| Harrison to Orta Nova | 4,418.76 mi (7,111.31 km) |
| Harrison to Orte | 4,232.34 mi (6,811.29 km) |
| Harrison to Ortona | 4,324.05 mi (6,958.88 km) |
| Harrison to Orvieto | 4,211.17 mi (6,777.23 km) |
| Harrison to Orzinuovi | 4,026.06 mi (6,479.32 km) |
| Harrison to Osimo | 4,243.68 mi (6,829.54 km) |
| Harrison to Ospitaletto | 4,026.98 mi (6,480.80 km) |
| Harrison to Ostuni | 4,522.92 mi (7,278.94 km) |
| Harrison to Ottaviano | 4,382.65 mi (7,053.20 km) |
| Harrison to Ovada | 3,995.32 mi (6,429.84 km) |
| Harrison to Ozieri | 4,147.45 mi (6,674.67 km) |
| Harrison to Paceco | 4,403.14 mi (7,086.16 km) |
